A number of isoindole-type compounds are known in the prior art. Recently, in German Offenlegungsschrift No. 2,165,651 a group of isoindole-1,3-diones which are useful as herbicides was disclosed. The general formula for the isoindole-1,3-diones is as follows: ##STR1## wherein R may be an aryl, aralkyl or benzyl optionally substituted with 1 to 5 halogen atoms; hydroxy, nitro, cyano, thiocyano, carboxy, halogenated alkyl, or alkyl, or alkoxy, lower alkylthio, phenyl groupings and a group having the configuration --0--CH.sub.2 A may also be substituted therein, wherein A is a phenyl or a naphthyl group, wherein the phenyl group may have one or more substitutions therein, such as halogen atoms, nitro groupings, lower alkyl groupings or lower alkoxy groupings.
Typical of the compounds disclosed in the Offenlegungsschrift is the compound of Example 1: ##STR2## It should be emphasized that several thousand compounds are disclosed within the broad description of the Offenlegungsschrift.
The compounds of the present invention result from efforts to develop superior herbicidal compounds.